With advances in electronic technologies, the requirement for the electrical conducting performance between a chip module and a circuit board is stringent increasingly. Generally, the surfaces of the multiple pins of the chip module and the multiple terminals of an electrical connector tend to be contaminated by dust. Alternatively, during the process of soldering the electrical connector to the circuit board, the smoke of soldering flux also tends to cover the surfaces of the terminals that forms grime on the surfaces of the terminals. Said dust and grime greatly increase contact impedance between the pins and terminals, and thus severely deteriorate electrical conductivity therebetween. Thereby, how to reduce the contact impedance becomes extremely important.
Presently, there exist terminals with two different structures. The first structure is an improved terminal and is disclosed in China Patent Number 97202231.7. The improved terminal has two side conducting pieces and an elastic piece used for plugging pin of a chip module and for contacting and conducting. However, when a computer host is assembled and during the early stage of powering on, because the surfaces of said two side conducting pieces and the elastic piece are glossy with low coefficient of friction, dust and grime are hard to be scraped temporarily when the pins are plug into the improved terminals. It is necessary to disassemble the computer host and use a driving means in the electrical connector to scrape the pins with the two side conducting pieces and the elastic piece for several times for thinning and removing the dust and grime. Then normal power-on can be truly realized. Thereby, there is a conducting problem during powering on for the first structure.
The second structure is a conductive clip disclosed in China Patent Number 01255459.6. The metal material of the conductive clip is cut to form a slide trench for connecting to a pin. Because the slide trench is formed by cutting, there exist tiny burrs on the inner surface thereof, making the surface coarse with a large coefficient of friction. When the pin plugs into the slide trench, the inner surface of the slide trench tends to scrape dust and grime, and thus reducing effectively the contact impedance. Thereby, after the computer is assembled, initial power-on can be performed smoothly.
However, practically, when the inner surface of the slide trench scrapes the dust and grime, the gold plating layers used for preventing oxidation on the pin and the conductive clip are scraped as well, which makes copper or other metals for electrical conduction exposed in the air. The exposed metal materials tend to react with oxygen and produce oxides, which definitely will increase the contact impedance and deteriorate conduction between the pin and the conductive clip. Even worse, the electrical conduction will be broken.
Accordingly, it is essential to design a novel electrical connector, which can solve the problem of the inferior conduction during power-on, and also can guarantee continuous electrical conduction.